There are so many cases of causing deformities due to alveolar bone in malformed maxillofacial patients. For example, those can be called patients with cleft lips and palates, jutting chins, deformation, and edentulous patients arising from traumas.
In case of a child with cleft lip and palate, it has a cicatrix after an early surgical operation and therefore meets with an impediment to growth of bone to cause deformation of jawbone. As a chin is normally growing despite abnormal growth of maxilla, the circumstance around a nose becomes to be recessed (undergrowth of upper jawbone) or the chin becomes to be protruded (overgrowth of lower jawbone). For solving these troubles, it is usual to conduct a corrective surgery for maxilla and chin in the end of the season when the maxilla is growing (a teenage), which means a surgical procedure to pull an undergrown maxilla frontward so as to revive the volume of the central portion in face or push a chin backward so as to make the chin shown smaller, with which a corrective treatment for teeth is accompanied to make rows of teeth fit well each other between the top and the bottom.
With respect to a jutting chin, there may be two cases of bad and acceptable teeth engagements. The latter can be correctable by simple surgery, whereas the former is inevitable to have surgery and correction. If even a correction is not contributable to occlusion because a jutting chin is too excessive, it is necessary to perform surgery for push the whole body of jaw including teeth and alveolar, which is regarded as the greatest surgery in the cases called jutting chins. It is also necessary to perform a dental correction before and after such surgery because the surgery can not be still acceptable thereto.
In other words, it is impossible for the cleft lip and palate and the jutting chin to be with a teeth shift by way of a corrective treatment in a classic manner because of discontinuity of alveolar, from which there are generated a malocclusion with lateral disharmony of maxilla due to cicatrix tissues after surgery, and a failure of thrive of intermediate face due to a frontward undergrowth of maxilla after surgery.
As a way for remedying faces and reconstructing rows of teeth for deformed patients and edentulous patients arising from traumas, it is required to perform surgery such as alveolar bone distraction or extension for frontward and backward teeth shifts, or a corrective treatment for prosthetic restoration.
As a surgical treatment for the deformed maxillofacial patients and defective patients, for the purpose of increasing a length of chin bone in inherent and acquired deformities, it is possible to result in an appropriate face and occlusion by adjusting a direction of distraction with a cutoff position and angle of bone. To do this, jawbone distractors are needed and can be briefly classified into extra-oral and intra-oral types.
An extra-oral distractor is an apparatus that is installed out of an oral cavity and controlled at the outside of the skin, advantageous in simplicity of installation, easiness of handling, controllability of distracting direction and so on, but inconvenient for a social life and may remain a permanent scar on the face.
An intra-oral distractor is an apparatus that is installed within an oral cavity, being widely used due to the shortness of the extra-oral one. However, even the intra-oral distractor may also cause various problems involved in aesthetic view, life convenience, complication and so on because its control part is located out of the oral cavity.
With the development of medial machinery and arts, corrective treatments have been diversified through surgical operations at maxillofacial parts. Among them, a technique of bone distraction has been being used to extend horizontal and vertical lengths of maxilla and chip and broaden an arch. The horizontal bone distraction has acted as a limit to clinical application because of its structural property in the bone distractor.
In recent years, being published are the studies about influences of bone distraction to peripheral tissues during bone distraction, particularly various analyses about influences of continuous, interrupted-continuous and intermittent forces to bone distraction, but still in shortness of objective materials since it is difficult to control minute forces due to a mechanical limitation of the distractor. Furthermore, during bone distraction, the feature of bone distractor necessitating external control may cause a complication such as an inflammation and a skin cicatrix due to contagion from an external projection. Therefore, there is a need for a jawbone distractor capable of being controlled more precisely without any external projection, hence free from a complication.
Generally, bone distracters being commercialized these days are mostly related to vertical bone distraction for recovering vertically defected bones, but horizontal alveolar shifters highly usable for corrective treatment region are almost not applied. Therefore, it is also required an apparatus capable of horizontally shifting an alveolar bone as well as performing vertical bone distraction.
In regard to the current technology of bone distraction, there are accompanied with limitations and complications such that an inadequate distraction force may be applied to a reviving tissue to generate a newly deformed bone, a direction of distraction may be set due to a failure of setting a treatment plan, an error for a surgical process, and a misuse of an apparatus, and excessive distraction of soft tissues may cause damage to peripheral soft tissues.
Therefore, the present invention provides a jawbone distraction system capable of horizontally shifting an alveolar as well as allowing vertical bone distraction, being precisely controlled in a wires mode and free from a complication without any outward projection.